Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b1085ba8 authored by Lino Sanfilippo's avatar Lino Sanfilippo Committed by Eric Paris
Browse files

fanotify: if set by user unset FMODE_NONOTIFY before fsnotify_perm() is called 



Unsetting FMODE_NONOTIFY in fsnotify_open() is too late, since fsnotify_perm()
is called before. If FMODE_NONOTIFY is set fsnotify_perm() will skip permission
checks, so a user can still disable permission checks by setting this flag
in an open() call.
This patch corrects this by unsetting the flag before fsnotify_perm is called.

Signed-off-by: default avatarLino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: default avatarEric Paris <eparis@redhat.com>
parent 88d60c32

fs/namei.c

+3 −0
Original line number Diff line number Diff line
@@ -1748,6 +1748,9 @@ struct file *do_filp_open(int dfd, const char *pathname, 
	if (!(open_flag & O_CREAT))

		mode = 0;



	/* Must never be set by userspace */

	open_flag &= ~FMODE_NONOTIFY;



	/*

	 * O_SYNC is implemented as __O_SYNC|O_DSYNC.  As many places only

	 * check for O_DSYNC if the need any syncing at all we enforce it's

include/linux/fsnotify.h

+0 −3
Original line number Diff line number Diff line
@@ -235,9 +235,6 @@ static inline void fsnotify_open(struct file *file) 
	if (S_ISDIR(inode->i_mode))

		mask |= FS_ISDIR;



	/* FMODE_NONOTIFY must never be set from user */

	file->f_mode &= ~FMODE_NONOTIFY;



	fsnotify_parent(path, NULL, mask);

	fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);

}